TrochoidMagic

i know i'm safe here in cali... don't know why most auto stores be selling multi-grade oils but who cares. i use 10-30 and pour in 30 weight oil. ITS A ROTARY!

i don't buy in to that epa crap. its been heard that ford had to use 5-20 to get their cars in a specific smog number and mpg... but thats all it really is. ford also owning 1/3 of mazda, forces the change on it as well.

i can't believe acura is doing the same... my wive's TL uses 5-20, but after i changed it to 10-30, the temp mark went down a notch cooler.

from what an earlier post said: " thinner oil removes more heat" . that part is true, in theory. but my guess is that if the oil is TOO thin and simply washes off, what protection is there really if its mostly metal-to-metal with a oil coat thats as thin as water? i don't trust it. and with the oil injection calibrated to "max" on the lower rpm range, ur simply not getting enough oil to lube the rotors. i would really just run a modest amount of premix if u want to stay with 5-20.

just my 2c's.

TrochoidMagic

to the OP, have u read up on the premix thread?

anyway, if a TL can benefit from a 30 weight(multi grade or not) then our rotary must be able to. who cares of 1-2 mpg savings? that's all the reason its mandated for... do u care of a 1-2mpg saving or maybe a lil higher hc emissions? or do u care about ur motor?

choose one.

TrochoidMagic

hmmm, couldn't post earlier. but anyway,

got to make it short. honda insight(its a hybrid) uses 0-20 oil. and among others.
those engines are built with tight clearances. not for racing, but for efficiency. they are not high output cars, so they can get away with a light oil and do it safely. it makes sense behind honda's engineering to use a 20wt in there, even a 0-20 at that. but not for our cars. so for the love of god, can we all just use 30wt in here for the sake of argument that it won't have any damaging affect on our car?

kennyfrc1

iTrader: (6)

savedsol

Mine likes starting in the winter with 5W-20 much better. Rest of the year is 5W-30.

Nubo

Let's hope so, since Mazda specifies 5W30 oil for RX8 for most of the world...

TrochoidMagic

now be the man of the hour if u can pull up a article that states that. so that way we can stop on the arguments of..."is 5-20 good for my car?" question and just have ppl use what are acceptable for rotaries, despite what mazda's bullshit recommendations are. this is only assuming owners do it on there own descretion...not going against new EPA rulings of regulations if any for manufacturers to follow... hint hint.

TrochoidMagic

uh hmm, let me clarify. those mazda recommendations are for U.S. specs to use 5-20.

but nubo here says he agrees that its actually 5-30 that the rest of the world uses and believe its safe to use.

so use whats recommended for the rest of the world... guys. if ur lucky to be located in the rest of the world.

cheers

ken-x8

Those arguments will never stop.

Why would a manufacturer sling bull on a topic like this? They designed and built the car. They're on the hook for warranty work. Their reputation is on the line.

Ken

savedsol

And you're a newbie post *****. Stop it! Every time you post you are the next one to two posts as well! Use the freaking "edit" button.

nycgps

iTrader: (1)

Use whatever you feel *comfortable* with.

I use 5w30 Full Synthetic. Engine works. Pulls hard.

enuff' said

kennyfrc1

iTrader: (6)

I use 5w-20 to remove rusty bolts when I am out of WD-40

nycgps

iTrader: (1)

I thought Canola work the best ?

Nubo

One theory is that 5W20 was specified for this market in order to satisfy EPA requirements for Corporate Average Fuel Economy (CAFE). The lighter oil yields a slightly better fuel economy. Failure to meet the CAFE standards is an expensive proposition, so every little bit helps -- especially when you're selling a car that only gets 18 mpg (EPA estimate).

One could blow a hole in that argument by pointing out that the number of RX-8 sold is insignificant from a fleet-average point of view. So, I don't know. Maybe there are other pressures being brought to bear.

However, the fact remains that Mazda specifies 5W30 for other markets. And the fact remains that the preponderance of engine failures were in the markets where 5W20 is specified. And if I am not mistaken the predominant failure mode for those engines was lubrication failure.

Draw your own conclusions. But at the very least I think it shows that 5W30 is suitable for use in the RX-8.

nycgps

iTrader: (1)

5w30 FTW !

Silver_Surfer

Aaaaaaaa, WHy not go 1/2 5-20, 1/2 5-30= 5-25wt.

ken-x8

Too ****.

Like the 91 octane business if you live someplace (like I do) where they have 89 and 93. I keep thinking of fueling 50/50, but would not be able to stand the ridicule.

IMHO, if you're not comfortable with the 20 part of 5w20, using 5w30 makes perfect sense. There is a longstanding tradition of using one grade heavier oil than specified. Back in the days of single-weight oil you'd have to be conciencious about warmup with the heavier stuff. But with 5w30 you've still got the 5 when cold, so warmup would be normal.

Ken

Icemark

Gonna call BS on that... at cold start, there is no difference between a 5W-20 and 5W-30.

Just as a raw example, Castrol GTX 5W30 has almost the same exact pour temp and low temp crank viscosity as Castrol GTX 5W20 until the oil gets to 100F.

So you are dreaming if there is any difference on a cold start between 5W20 and 5W30 conventional oils.

Infact the low temp crank viscosity even a 5W50 is going to be the same as the 5W30

savedsol

Please go ahead as these are my observations only and there is no way to prove an engine starts easier. But believe me when I stand by my convictions that starting in 20 deg weather is smoother and quieter with 5W-20.

mac11

iTrader: (1)

Actually its common for oils with the same vicosity rating to have a different actual viscosity and quite commong for something like the 5/20 v. 5/30 in question to have a much different cold viscosity. It all depends on exactly what has been mixed wth the base oils. And you can even have instances where a 5/30 will be thicker than a 10/30 at startup as 5 and 10 weight oils are rated for visosity at different temperatures. So in real world temps, say 0*F, the 5w can be thicker.


For example AMSoil 5w20 is thinner at -30*C than AMSoil 5w30.

TYPICAL TECHNICAL PROPERTIES (Revised as of 1/06)
AMSOIL XL 5W-20 SYNTHETIC MOTOR OIL 5W-20
(XLM)

Kinematic Viscosity @ 100°C, cSt (ASTM D-445)- 8.5
Kinematic Viscosity @ 40°C, cSt (ASTM D-445) - 45.4
Viscosity Index (ASTM D-2270) - 165
CCS Viscosity, cP @ (°C) (ASTM D-5293) - 3818 (-30)
Flash Point °C (°F) (ASTM D-92) - 226 (439)
Fire Point °C (°F) (ASTM D-92) - 236 (457)
Pour Point °C (°F) (ASTM D-97) --- -43 (-45)
Noack Volatility, % weight loss (g/100g) (ASTM D-5800)- 10.7
High Temperature/High Shear Viscosity@ 150°C and 1.0 X 106 s-1, cP (ASTM D-4683) - 2.7
Four Ball Wear Test @ 40 kgf, 75°C,1200 rpm, 1 hour, scar diameter, mm (ASTM D-4172) - 0.43
Total Base Number (ASTM D-2896) - 9.0


TYPICAL TECHNICAL PROPERTIES (Revised as of 12/06)
AMSOIL XL 5W-30 SYNTHETIC MOTOR OIL 5W-30
(XLF)

Kinematic Viscosity @ 100°C, cSt (ASTM D-445) - 10.5
Kinematic Viscosity @ 40°C, cSt (ASTM D-445) - 58.2
Viscosity Index (ASTM D-2270) - 173
CCS Viscosity, cP @ (°C) (ASTM D-5293) - 4341 (-30)
Flash Point °C (°F) (ASTM D-92) - 234 (453)
Fire Point °C (°F) (ASTM D-92)- 246 (475)
Pour Point °C (°F) (ASTM D-97) --- -43 (-45)
Noack Volatility, % weight loss (g/100g) (ASTM D-5800) - 8.9
High Temperature/High Shear Viscosity@ 150°C and 1.0 X 106 s-1, cP (ASTM D-4683) 3.2
Four Ball Wear Test @ 40 kgf, 75°C,1200 rpm, 1 hour, scar diameter, mm (ASTM D-4172) - 0.43
Total Base Number (ASTM D-2896) - 9.0

Icemark

quieter? On a rotary engine? ... yeah I guess there is not as much valve slap right?

Icemark

Looks like the cold temp pour point is exactly the same... of course if it was not synthetics, you would probably see the cold temp viscosity and standard viscosity rather similar too, just like the four ball wear test (metal to metal contact) is.

savedsol

Ha ha ha must be that... ahole.

mac11

iTrader: (1)

pour point is the same because the likely use the same base stock. That only further enhances my statement that the additive packages used to give it the specific weight charactoistics change the viscosity as the temperates changes.

csl

http://trust-power.com/10oil/spec_f3_respec.html